Controlling Concrete Curing Temperatures

In our latest blog, Roger Rattue, regional director in the materials testing division at SOCOTEC, explains what steps the business has taken to ensure our clients continue to receive high quality results.

This year the UK has experienced a relatively warm summer, and while this is great for trips to the beach and days out with the kids, it does make life harder for concrete testing laboratories. This is because as the weather gets hotter, the temperature for testing concrete becomes even more difficult to control, which ultimately has an impact on the accuracy and quality of results. But why has this latest UKAS update got so many people hot under the collar?

Mercury rising

In the UK, 20°C is considered the ideal temperature for curing concrete cubes, and as minor variations in temperature don’t have any effect on the strength of the concrete, a fluctuation of 2°C is permitted. However, while this maximum temperature is stipulated in BS EN 12390-2:2009*, the update from UKAS revealed that these conditions haven’t been met by a significant number of laboratories. In these instances, clients were receiving reports with disclaimers attached indicating that temperatures may have exceeded 22°C during the curing process.

As a result, UKAS confirmed that as of 1 February 2014, all testing houses will now need to demonstrate that the temperature has not risen above 22°C, regardless of how hot it is outside. Although the BS EN standard hasn’t changed, it will no longer be possible to include a disclaimer alongside the test results – for most testing houses, this will require a complete overhaul of their concrete curing set up.

*Please note BS EN 12390-2:2009 has now been replaced by BS EN 12390-2:2019.

Greater control

You might have guessed it already, but the only way laboratories can ensure they maintain compliance with UKAS’ temperature limits is by investing in more advanced technology and facilities.

Here at SOCOTEC, we’ve taken the opportunity to invest more than £100,000 to further improve our laboratory facilities so that ambient temperature and water temperature is consistently controlled where curing tanks are stored. Our Uxbridge laboratory is one of the biggest in the UK, serving some of our largest customers, so we’ve created a permanent, enclosed temperature-controlled environment with data logging alarm systems installed, which give us even greater control and provide us with more accurate readings throughout the curing period.

While the update from UKAS won’t cause too much concern for laboratories such as ours, customers will benefit from added reassurance that their concrete cubes have been tested to the required standards. Looking ahead, this intervention may also contribute to sustaining the long-term quality of construction within the UK.